Container refrigeration systems are conventionally used for cooling the interiors of containers for use in sea transport or other transports.
For example, Patent Documents 1 and 2 disclose container refrigeration systems of this kind. As shown in FIGS. 6 and 7, a container refrigeration system (70) is assembled to the front opening of a container (C). A frame (71) of the container refrigeration system (70) has an exterior storage space (S1) formed in a lower part thereof to open onto the outside. Placed in the exterior storage space (S1) are a compressor (72), a condenser (73) and an external fan (74). The frame (71) has also an interior storage space (S2) formed in an upper part thereof to open onto the interior of the container (C). Placed in the interior storage space (S2) are an evaporator (75) and an internal fan (76). In the container refrigeration system (70), the compressor (72), the condenser (73), the evaporator (75) and other components are connected through refrigerant pipes to form a refrigerant circuit. In the container refrigeration system (70), the refrigerant circuit operates in a refrigeration cycle by circulating refrigerant therethrough, whereby the evaporator (75) cools the interior of the container (C).
The frame (71) of a container refrigeration system (70) of this kind further includes an electrical component box (80) mounted in a side face (the front face) thereof. The electrical component box (80) is formed in the shape of a box having an opening in the front and stores heavy electrical components, such as a breaker, a transformer and magnet switches, and light electrical components, such as control boards. The opening of the electrical component box (80) is covered with an outside lid (81). The outside lid (81) is provided with an operating part (81a) through which the user conducts operation mode change and other controls of the container refrigeration system (70).
Such an electrical component box (80) is disposed above the compressor (21) in the frame (71) because of space limitations imposed by installation spaces for the compressor (72) and other components. Therefore, the frame (71) includes support plates for supporting the bottom plate and the top plate of the electrical component box (80). The electrical component box (80) is fastened to the support plates by bolts and nuts.
A safety cover is attached to the opening of an electrical component box (80) of this kind inwardly of the outside lid (81). The safety cover has an opening formed to expose only the breaker in the electrical component box (80) to the outside. The other electrical components are covered with the safety cover. In other words, the safety cover prevents the user from touching the electrical components other than the breaker in turning on/off the breaker switch. Also attached to the electrical component box (80) are hinges or like fittings to allow the safety cover to open and close the opening. Thus, the electrical component box (80) is configured to allow the safety cover to be opened only in doing maintenance on the electrical components.    Patent Document 1: Published Japanese Patent Application No. 2004-353912    Patent Document 2: Published Japanese Patent Application No. 2004-325022